单项选择题
A. Download manufacturer printer drivers
B. Restart the printer spooler
C. Check for Microsoft Windows updates
D. Check Device Manager
单项选择题 After Microsoft Windows boots, a message appears stating that a service failed to start. Which of the following can be used to find more information about this error?（）
单项选择题 A virus scanner is running on a computer and scans all files currently in use. Why should a full scan be performed periodically?（）
单项选择题 Which of the following commands will show all active TCP/IP network connections?（）